types of output values in Qtp are as follow:

1) Standard output value
2) Text output value
3) Data base output value
4) xml output value (from application)
5) xm output value (from resources)

There r 6
1 Std
2 Txt
3 Txt area
4 Data base output value
5 xml output value (from application)
6 xm output value (from resources)

guys total there are 7 actually...let me explain in detail...

1. Standard OP 
2. Table OP
3. Text OP
4. Text Area OP
4. Database OP
6. XML output (from application)
7. XML output (from resources)

1. Standard OP: this ouput value is used to get a property
value of an runtime object in application for later input.
  Example: to get the text entered in a text box, or to get
button name or get items count in a weblist.

2. Table OP: this ouput value is used to get the data from
specified cell in a webtable. this option is not visible in
QTP. but u can impliment this thru standard output value.

3. Text OP: this output value is used to get some text from
the web application.

4. Text Area : this output value is used only for windows
application. and used to get text from specified area.

5. Database OP : to get the data from the data base using by
application.

6. XML from Application : to get the values from XML file
thats been using by application.

7. XML from Resources : to get the values from external XML
file to parameterize your test.

  if any queries , please mail to:
             nanda.dreddy@gmail.com

Regards..
Nanda